Lately Ive had some trouble with my IAC counts. I'm shooting for 5-10 and usually it will settle there and other times its 10-20. Its a new IAC but I never did the steps Ive read online to reset it? I didnt think I needed ti since it was new? Is the procedure the same with the EBL as far as pinning the a & b diagnostics ports?

 

Small bore engine like the 305 is going to like some timing, especially with aluminum heads. The L99 4.3 V8 ran up to 35* of timing at WOT and it has reverse cooleing system and cast-iron heads.

 

This may help... I reset mine a couple years ago I idle at about 5 steps and that is what I desire. Works OK as far as drivability. I never have had a stall past few years with IAC functioning. Likewise I never have a high idle.

7.4L TB...

 

No need to do a manual reset. The ECM resets the IAC at key-off if the engine had been running.

RBob.

 

You may have a leaky TB shaft or maybe the TB doesn't fully return. Or it's something like engine temp, closed vs open loop, actual commanded idle speed, accessory load, etc, etc. The short of it is, either figure out what the variable is or just set it so it never goes below 5 steps, and live with it sometimes being 15 or whatever.

 

So as far as adjusting the steps go I can adjust the throttle stop screw and should I immediately see the changes on the wud or after cycling the key and engine on and off?

 

key on engine off you should see the new steps on a twist of the TSS. If you adjusted the steps in .bin you need to reflash. Unless the car shows a diff coolant temp due to cool down then steps will vary.

 

well i been trying to figure out why i have 60* on my sa main table and only 38* on my wud...here is my .bin
can anyone read it and let me know what im doing wrong thanks for the help.

 

i guess im computer illertate...tryed uploading the file but wont let me

 

there now i ziped it!!

 

I didn't look at the bin but what about coolant comp or the base advance setting?

 

I'm looking at it and the only thing I see is that the "SA - Coolant Comp Bias SA" needs to be zeroed out. If the engine RPM is in the area (600 - 1000 RPM) where the SA in the Main table is 47.81*, that is the issue.

Sub off the 9.84* bias and it is 37.97*.

RBob.

 

RBob-is the ebl logic the same as gm on the air injection?
I'm in Kalifornia, so running all smog-in researching the gm logic it looks like it injects air to the headers during warm up/ all open loop, then on closed loop it diverts air to the cat. Diverts out if rich op/code set/decel/or high rpm when press greater than the relief valve.
I've tried both open and closed loop-the learn always has to shift the ve tables between the two; which has been frustrating me no end. However the gm logic makes sense of what it's been doing. If it's sending air to the headers then it would essentially be like an exhaust leak sucking in false air to the O2 sensors. Also I'm running a smog legal supercharger, so it taps air from the sc's pressure relief valve to feed the air system instead of the original smog pump-so it gets plenty of air.
So if air logic is the same, then I'll only learn the ve tables in closed loop.
Am I reading this correct?

 

There is no AIR support with EBL as far as i know.

 

Details:

The EBL P4 system sends ECM data to a laptop or PC running the What's Up Display program. It is simply the best and fastest data logger available for GM ECMs. The data stream contains all available engine and vehicle parameters.

Included on the EBL board is eight analog input channels. The data from these inputs is included real time with the ECM data. These analog inputs can be used for data logging WB O2 units, fuel pressure, and any other 0 to 5V linear device (accelerometer, oil pressure, oil temperature, suspension travel, and so on).

The software to run the engine is the result of years of effort. It has been enhanced to support engines from stock through high performance monsters. Handles boost to 30 psi. The EBL code provides functionality not found in stock ECMs. Wet N2O control, lean cruise, cranking prime pulses, ability to select open loop modes for cruise, deceleration or idle.

For example:
A real shift light
Soft touch rev limiter
1, 2 and 3-bar MAP support with boost SA retard and fuel multiplier tables
Spark tables are high resolution and full size up to 6,400 RPM
VE tables are high resolution and full size up to 8,000 RPM
Acceleration enrichment (AE) tables have been expanded
Changes to the fueling algorithms have been made to provide a smoother, stronger running engine.
Electric fan control for 2 fans
N2O wet system control: minimum MPH, TPS threshold, RPM window. Arming input
Smart A/C control: PE disable, upper/lower RPM shutoff, re-enable delay
Lean cruise mode for better fuel mileage
Open loop fueling modes
N-Alpha mode
Emissions functions: EGR, CCP, A.I.R. and closed loop fueling

 

my bad, i wasn't aware the P4 was offering AIR support! i was a bit too hasty then, sorry.

 

The way the AIR works is very similar to GM implementation of it. There are three places the air can be directed:

to cat-con
to port (exhaust manifold)
to atmosphere (divert mode)

When the engine is first started and the ECM is in open loop, the air is directed to port. It's been a while since I've looked at this, but IIRC, when in PE mode, or over a certain load or RPM, the air gets diverted.

Once the ECM goes closed loop air to port is never used again. For the most part it goes to the car-con. With the exception of high RPM/load or PE mode, at which time the air gets diverted.

Best bet while tuning is to set the enable CTS high, this forces the air to always be diverted.

RBob.

 

thanks rbob it was that!!!
thank you again you been an efi god....

 

If there are efiGods, then RBob is Zeus residing in Pennsylvania on Olympus.

 

im having a lil dilema...i took my engine out to fill the block with cement and a cam change and some new main cap arp studs...when i put it back in the car i put the balancer at 6* btdc on #1 and phase the distributor to #1 plug...got car started it runs ok with old tune up..but when i unplug the tanwire to check timing it dies!!!...with the tan wire connected it shows 6* btdc...so with the ebl i dont have to unplug the tan wire to check timing?
also when i rev it ,it stays at 6* but my sa main table its at 32*
and on the wud shows exactly that...how come timing is not picking up at the crank when i rev it up?

 

Sounds like the ebl is not advancing timing ... have u checked all ur connections wiring etc.

91' bird 305 TBI T-5, trick flow heads, 4.10 gears, full UMI setup, track times coming soon!

 

[quote=1991sleeper;5765906]Sounds like the ebl is not advancing timing ... have u checked all ur connections wiring etc.




everything is pluged in...what wires are the ones that advance the timing?
the ones that plug into the dist?

 

I'm not entirely following but it sounds like you set it so it's 6° BTDC with the tan wire connected. Advance the dist until you get your 6° BTDC with the wire DISconnected. It should run unless it's a very hot setup. I assume it's stalling because it goes from 6° BTDC to 26° ATDC when you unplug. At least that's my best interpretation of what's happening.

 

kevm, same way i got it. i'd suggest trying to advance the distributor with the EST (tan wire) disconnected until it will start (watch out for flooding), and then go from there.
btw some engines have a misleading way of timing indication. or shall i say some combinations of timing cover tab and balancers.. it may read way off when using an early style balancer with a late style timing tab or vice versa. i forget by how much but i'm just throwing this out because it threw me way off and took a while to figure it out on a buddy's Blueprint 355 crate.

 

When the ECM sets code 42 it is locked in. The ECM will no longer control the timing. So once the EST/BYPASS has been opened with the engine running need to key-off for at least 10 seconds then restart the engine.

Stalling when opening the EST/BYPASS connector with already low timing will easily cause the engine to stall. To rough in the timing first leave the EST/BYPASS closed, look at the WUD's SA value, and rotate the distributor to match.

RBob.

 

If I understand the objective..... ( keep the sensor from being torched to death while having still fast enough to run the engine )
Keep the sensor close enough to the exhaust ports as practical for fast response, while at the same time keeping it far enough out of the exhaust stream to not burn it up....

I'd weld a stub onto the exhaust pipe. Just a "T" type thing just long enough so that the end of the sensor is about 1/8 inch out of the pipe. Maybe 1/2 inch. I don't really know, nor am I really qualified to guess. Weld the bung on the end of this stub, so that when the sensor is screwed in, it senses the flow past it, but not directly on it.
Then, I'd slip onto that stub a heat sink, something like this one...
http://www.qualitekengineers.com/rou...nk-499549.html

I'm not enough of an aerodynamic engineer to guess how big of a hole in the end of the stub, but it seems the smaller the better heat isolation, while at the same time it seems that a small hole would slow the response. I dunno.....
For me, I'd likely want something that screws together, so that the length of the stub can be changed, like a screw in plumbing nipple, and leave the hole in the end full size.
The longer the stub, the better the isolation. ( or so it seems )

 

I actually found it, took long enough too. Here is a link w/description...

http://www.innovatemotorsports.com/x...cat=250&page=2

 

Wow ! 'Spensive !
OTOH, as long as it works.

 

Hey all, So ive been busy squaring away other problems on the f-body. Still having my cold start issue, which i believe i finally found my vacuum leak. When i press the brake pedal in at park, my rpm slightly increases? Going to re do my brake booster lines as one is actually kinked up. But thats not the issue i finally found. So after doing a cold start with my buddy around (old school mechanic) he believed something was going on with my Spark, well we hook my labtop up next morning and fire up Ebl WUD. Start the car, with out putting my foot on the gas just slightly to keep it alive, the rpms shutter and hunt between 400-1000 pretty radically, but i noticed my Spark advance was jumping up and down from 20 to 4 and any number in between, while this was going on Spark Retard was going up to 4-6. Once i put my foot on the gas slightly it evens out and spark advance remains constant. Once its warm it never does it again. Could it just be the vacuum leak (cold air) causing it to be very radical and once warm it doesnt affect it? Or is there something within the spark system that can be caused by cold weather?

 

There's both a start-up and idle spark settings.
I use the idle spark for just exactly what you're describing. It essentially disables corrections at idle, resulting in a static, fixed spark advance at idle. The engine still hunts a bit due to the cam, ( more of a rolling surge sometimes, but not all the time ) but the idle is much, much smoother as a result of a fixed idle spark at a reasonable number, like 22 or so. ( more or less depending on what works for your engine )

 

Another option for rolling idle improvement is open loop idle. That command a set A/F with no NB 02 sensor feedback. I believe there is a flag to check.

 

hmmm sounds like it could be something open loop related, as its very noticeable at a cold start. Im going to get this vacuum leak situated first and see if anything changes.

 

With cammed engines I try to tighten up the inputs. As an example, in the LT-5 there are are spark tables adding/removing timing depending on the rpm error.
I reduce the amount of timing in those tables to prevent the idle from running away and compounding itself.

 

Guys quick question, I spliced the secondary fan control in the back of the ECM, but now I have to relocate the secondary fan switch wire that originally leads to the passenger side cylinder head. I pulled that secondary fan switch out because of the turbo, as I wanted to eliminate all connection locations from the heat, but I never got around to relocating to the front of the intake manifold, and of course now I cannot find where I placed that switch. Don't wanna by another secondary sensor if I can just splice the secondary fan wire into the primary fan control sensor, the coolant temp sensor. What do you guys think, or should I just pony up the cash for a new secondary fan sensor...

Edit: RBob just reached out to me and told me what needs to be done, will wrap things up in a few minutes and follow up with the results...

Edit II: Bad secondary relay, despite clicking when tested, it was bad. Replaced with a new unit, and the system works flawless, no need to connect secondary fan switch wire...

 

Ditto ! I've reduced the range on a lot of things, which helped smooth things considerably.

 

this might sound stupid..lol...but the other day I took my dash apart and when I put it back together somehow I lost the small nut that holds the connector for the usb port cable on the eblp4...where can I get one of this?
I looked thru elctical stores...none of the ones I tried worked...rbob can I buy any from you?
thanks.

 

Hello all,

I've been having an issue with my car that I believe could be either a lack of fuel or spark. The engine hesitates when I give it a lot of throttle and if given enough throttle, it will backfire from both the throttle body and the exhaust.

I replaced my spark plugs this week to no effect although I did come to find that the old plugs were extremely wet. I know my tune has too much AE but this is something that's always existed.

I use to be able to do WOT throttle runs and would have a slight pop from the exhaust but the engine would pull fine after the AE fuel decayed.

Today, if I try to do a WOT run, all I get is a bunch of chugging and pops between intermittent accelerations, and for the first time during WOT, my WB is reading lean.



I've been going through all of my previous pictures of changes I made to my car and I cant find any changes that were made around the time that the issue began. It makes me think that either something is clogged or something is faulty in regards to spark/fuel.

Just wanted to post here to see if anything could be spotted in my datalog before I create my own thread.

I'm thinking I might install an FPR monitor in the dash or EBL so I could monitor FP realtime and see if its dropping off during WOT. Any ideas or suggestions would be helpful.

Thank you!

 

Cflick,

Well at least now I know it isn't my imagination. Thanks for confirming.

 

But would this help with Cold start(only) conditions? Its very odd, car runs GREAT when warmed up, feels very strong and right there, but my knock count when in cold start and not having foot on the gas just goes out the roof (causing the SArt to kick in and retard things down) idk i think something mechanical is wrong with my ignition system. I think im not getting full combustion or something and its causing misfire to happen causing knock causing SA to retard. Time to check my Dizzy!

On another note, i was watching Playback from a Datalog from the other day, and notice that once i go WOT, my DC% jumps instantly and is always hitting 100%+ around 3000rpm, i seen 103%DC the other day; is that even possible? If not why does it even show the value of 103? Any who looks like im out of fuel very early?

 

Possibly a little rough, causing vibration, causing the exhaust to bang on the frame, or some such ? I'd look for something mechanical due to cold idle vibration.
( unless, of course, you can actually hear detonation )

That's telling you that the comfuser is calculating that you need 103% of what's available.
At around 90% ( more or less ) injectors go "static" and control is totally lost.
( means they simply do not have time to close and open again, so they effectively stay open, but not fully open as they try to close. )
Static injectors flow a lot of fuel ! If you're still going lean, then you need bigger injectors, higher fuel pressure, or both.
Strive to keep the injectors below 85% or so under the most demanding conditions.
( that would be WOT high load high RPM )

 

What he said!

 

Thanks Guys!! Im not sure it could possibly be a exterior thing causing false knock, but yes i cant hear actual detonation. I can hear the motor missing slightly at times, so it pushes me toward something in my ignition system. The car was sitting for 2-1/2 years and was getting a water leak into the engine bay right at the location of the distributor (Air filter had rust inside of it) so i need to check any ways.

Damn ok i dont think 3K Rpm is high rpm lol, im running out pretty early no? If max should be around 85% that means my motor was asking for 18% more fuel at that moment? When they go static is that bad? Also what do you mean static injectors flow a lot of fuel' ? I knew i was running lean (mild-moderate built 350) but i didnt know that bad. Im running 61PPH injectors at (checked FP) 11.5PSI. Waiting to get a AFPR in there with my 65PPH injectors soon.

 

Ghetto, are you using a vac-ref FPR on that build? also, might want to check your plug gaps after the distri checks out fine. other than that, what's your SA and AFR at cold idle?
edit: sorry just read your last sentence where you state you want to put in an AFPR soon. while you're at it, get a vac-referenced one (VRFPR). prolly want to up fuel pressure to 15 psi, change BPC according to EBL Utility/BPC spreadsheet, and start over with the tune.

I think that's exactly what I'd want to look at. If your fueling has been fine before (not as lean), and suddenly is, I'd suspect one of the fuel system components as the culprit (could be injectors, fuel pump, filter...). You can check fuel pressure with a mech. gauge as well, but want to check it during load as well so you see the pump is still flowing up to par.

 

Honestly good point! I havent looked at my plugs since i got to tuning and rbob has once stated i should check , Plus they are the original plugs i put in the motor when i dropped it in 4years ago (motor has around 25-30k on it)
Ive been reading alot on the VRFPRvsAFPR, and just slightly scared on drilling a hole into my manifold for vacuum, ect. Just seems like some work that i could by pass by getting a afpr? Or is the vfpr that much better?

Well the thing is this motor has always been running lean, just never got to see how bad it actually is. Then it sat for 2-1/2 years and now random cold start issues, so im guessing something went bad within that time sitting.

 

Plugs are your eyes into the engine Other than that and looking at the exhaust output (oxygen sensor, EGT) there's not a lot we can do to tell what's going on in there. Should put in new ones anyway at that milage too imho.
FPR: depending on how many vac ports you have, you can just tap into one of the existing ones to feed your VRFPR, so I'm not sure where you got the drilling part from. Most VR- or AFPR variants for TBI you can just install instead of the stock fixed FPR in the stock location, so imho that's quite an easy and clean way to do it. Going VRFPR on anything but the cheapest low-perf build is a must imho, and they're not really expensive anyways. As a bandaid you can adjust the stock FPR, but just by a small amount and it's not vacuum referenced, which means depending on your injectors & fuel pressure, you'll end up with your idle too rich or too lean on WOT. Basically, a VRFPR extends your usable injector range quite a bit, because you'll have lower fuel pressure at idle and decel (high vacuum), but more fuel pressure at load and WOT (low vacuum).

 

Dont need to. Drill a hole in brake booster fitting and add a nipple....
Only problem with that is you go full throttle when you hit brakes!! LOL.

As Ownor says... However the car just run better all around. I think it works well with AE and transitions overall.

 

oh wow idk why i didnt think of my Vaccum ports on the TB!! I have my Thermac air cleaner vac port plugged, would that be adequate vacuum? I want the best i can get and looks like you guys are right about best Atomization of fuel at idle/WOT. What VRFPR are you guys using? Can you point me in a direction of one? Also with the VRFPR do i need to still get the 18psi spring or no?

Well i only had time to pull my #1 plug and take a look. I have no knowledge what so ever how to look at a plug, I just know how to look for oil fouling and rich/cold mixture's. heres my number #1, ready to change?







Im glad you said check gapping! This thing was set at .063! i adjusted down to stock setting .035 so we will see, but this now has me thinking towards all of my plugs are gapped incorrectly.

 

sorry just seen this, whats cold to you? instant cold start? or after idling for a sec? Well my SA stays at 20-21* and my AFR starts at about 11.5 and slowly climbs to 13.5.

 

plug not looking too bad imho, brown/tan-ish and no melt-down spots on either center electrode or ground electrode, so not really worn. no oil leaks either. there are about a thousand of pics when you google spark plug chart on how to read them. i'd primarily try to read mixtures/distribution from that, some also read timing stuff from the plugs but myself i haven't done that.
plug shows brown on one side and insulator ceramic white/natural on one side, not sure what that means but i'd guess the brown side is the one closer to the intake valve or the side facing into the chamber.. not sure if that's a problem, but i'd think it should be color all around the insulator tip.

edit: just saw you said gap was .063! much too wide i'd think, although i think a too wide gap would cause a miss at higher loads/speeds. i remember Cflick writing at some point in this thread about plug gaps and their influences on combustion dynamics. only thing that got stuck in my head is this analogy (or fact, even?): a wider gap will allow more air and fuel molecules into the area of the ignition arc, which will help light-off in low load situations (idle, cruise) but might blow out the spark at higher load (WOT, acceleration). vice versa for a too tight gap. i hope i got that right

 

TPI guys like Kirban. Some say stay away from Holley? TOP DOWN SOLUTIONS sells the spring one step stronger than early stock TBI. The only TBI specific variable A-F FPR I am aware of is Aeromotive and that is what I use. DIVERSIFIED CROSSFIRE SOLUTIONS possible has one as well.